The average round-trip fare within the US is now above $500 as air fares have leapt 10.7% during the last five years.
Domestic ticket prices continue to keep ahead of inflation, rising 2.7% against a 2.1 percent increase in the consumer price index.
Data from Airlines Reporting Corp., which records transactions for airlines and travel agencies, shows the average round-trip flight including taxes rose to $509.15 during the first half of the year.
"Airlines have reduced the number of seats while more people want to fly because of the economic recovery which leads to higher airfares," said Chuck Thackston, ARC managing director of data and analytics.
"This trend in airfares is likely to continue for the near future, as the economy continues to grow."
Also after a spate of mergers, 80% of the domestic market is now in the control of just four carriers – American Airlines Group, Delta Air Lines, Southwest Airlines and United Airlines.
In the second quarter the big four reported combined profits of almost $3 billion.
